1. Field of the Invention
The present invention relates to an image processing apparatus with enlarging function for electronic enlargement of a designated area within the image field.
2. Related Background Art
In the field of image pickup device capable of digital processing of image signals, there have been proposed electronic image magnification enlarging means such as the so-called electronic zooming function for electronically zooming up the object in a similar manner as in the optical zooming, and the electronic close-up function for instantaneously enlarging a part of the image, obtained from an image pickup device, to a predetermined magnification (for example doubled or tripled size).
In the following there will be explained, with reference to FIG. 1, such conventional electronic image magnification enlarging means. FIG. 1 is a block diagram of a video camera, for explaining such conventional image magnification enlarging means, wherein shown are a lens 1 for forming the image of an unrepresented object; an image pickup device 2 for converting the optical signals, inputting from the lens 1, into electrical signals; an analog-to-digital (A/D) converter 3 for converting the photoelectrically converted analog signals into digital signals; a first camera signal processing circuit 4 for applying predetermined processes, such as gamma processes separately on the color signals and luminance signal, on the signals obtained by A/D conversion in the A/D converter 3; an enlargement process circuit (electronic image magnification enlarging means) 5 for effecting an enlargement process on the image signals output from the first camera signal processing circuit 4; a second camera signal processing circuit 6 for applying a predetermined process, such as the addition of synchronization signals, to the image signal output from the enlargement process circuit 5; a digital-to-analog (D/A) converter 7 for converting the digital signals, output from the second camera signal processing circuit 6, into analog signals; an enlargement process execution switch 8 for enabling the photographer to input an execution command signal for the enlargement of the image signals by the enlargement process circuit 5; and a microcomputer 9 for controlling the entire video camera.
In the video camera of the above-explained configuration, the light from an object is focused, through the lens 1 and an unrepresented diaphragm (iris) mechanism, on the image pickup device 2 and is converted into electrical signals. The output electrical signals are supplied, for example through a correlated double sampling (CDS) circuit (not shown), to the A/D converter 3 for conversion into digital signals. Thus converted digital signals are supplied to the first camera signal processing circuit 4 for predetermined processes, and supplied, either directly or after an enlargement process in the enlargement process circuit 5, to the second camera signal processing circuit 6. After a predetermined process therein, the signals are converted into analog signal in the D/A converter 7 and output to an unrepresented video cassette recorder or the like.
The enlargement process by the enlargement process circuit 5 is executed by an execution command signal, which is input by the actuation of the enlargement process execution switch 8 by the photographer and is received by the microcomputer 9.
In the following there will be explained, with reference to FIGS. 2A to 2D, an example of image enlargement by linear interpolation. In case an original image (hatched area) in FIG. 2A is enlarged as shown in FIG. 2B, the relationship of the scanning lines in the original image (FIG. 2A) and the enlarged image (FIG. 2B) becomes as shown in FIGS. 2C and 2D. For converting the enlarged image in FIG. 2B into the standard television signals, it is necessary to prepare scanning lines of interpolated signals 1 to 7, represented by broken lines, from scanning lines A to F, represented by solid lines in FIG. 2D. Such broken-lined scanning lines can be obtained by the addition of the solid-lined scanning lines weighted according to the distances thereof. Such linear interpolation, applied in the vertical and horizontal directions, enables enlargement of the original image with an arbitrary rate of enlargement.
FIG. 3 is a block diagram showing an example of the enlargement process circuit 5, wherein shown are a memory circuit 10 for storing the image signals received from the first camera signal process circuit 4 (cf. FIG. 1) and outputting the signals of an n-th scanning line designated by a memory readout control signal and the signals of an (nxe2x88x921)-th scanning line, preceded by a 1H period; a memory control signal generation circuit 11 for generating a memory control signal for controlling the data write-in and read-out of the memory circuit 10; an enlargement ratio determination circuit 12 for determining the ratio and position of enlargement in the enlargement process by the enlargement process circuit 5; an enlargement coefficient generation circuit 13 for generating an interpolation coefficient according to the ratio of enlargement determined by the enlargement ratio determination circuit 12; a first multiplier 14 for multiplying the signals of the n-th scanning line from the memory circuit 10 with the interpolation coefficient from the interpolation coefficient generation circuit 13; a second multiplier 15 for multiplying the signals of the (nxe2x88x921)-th scanning line from the memory circuit 10 with the interpolation coefficient from the interpolation coefficient generation circuit 13; an adder 16 for adding the output signals of the first multiplier 14 and of the second multiplier 15; and a microcomputer interface circuit 17 for receiving the information on the enlargement ratio and enlargement position, output from the microcomputer 9 (cf. FIG. 1).
From the memory circuit 10 storing the input image signals, there are read the signals of the n-th scanning line and those of the (nxe2x88x921)-th scanning line in response to the memory control signals generated from the memory control signal generation circuit 11. At the same time the interpolation coefficient generation circuit 13 generates the interpolation coefficients, corresponding to the distances between the interpolated scanning line and the n-th and (nxe2x88x921)th scanning lines. Then the first and second multipliers 14, 15 effect multiplications of the signals of the n-th and (nxe2x88x921)-th scanning lines respectively with the interpolation coefficients and the multiplied signals are added by the adder 16 to provide linearly added signals.
The enlarged image signals can be obtained by the linear interpolation explained above.
In such conventional configuration, however, the position of enlargement of the image obtained from the image pickup device is determined in advance, and it has been difficult for the photographer to arbitrarily select the position of enlargement.
Also the photographer is unable to arbitrarily determine the center position of the image enlargement and the image angle, and is unable to know, in advance, the area of the enlarged image.
In consideration of the above-mentioned drawbacks of the prior art, a first object of the present invention is to provide an image pickup device which enables the photographer, in simple manner, to arbitrarily select the position of execution of the image enlargement process such as the electronic zooming function or the electronic close-up function on the image area.
The above-mentioned object can be attained, according to a preferred embodiment of the present invention, by an image processing apparatus provided with enlargement process means for enlarging the image signals output from an image pickup device, comprising execution position selecting means for selecting the position of execution of the enlargement process by the enlargement process means.
The foregoing object can be attained, according to another preferred embodiment of the present invention, by an image processing apparatus provided with enlargement process means for enlarging the image signals output from an image pickup device, comprising execution position selecting means for selecting the position of execution of the enlargement process by the enlargement process means, and display means for displaying the state of selection by the execution position selecting means.
Also the foregoing object can be attained, according to another preferred embodiment of the present invention, by an image processing apparatus provided with enlargement process means for enlarging the image signals output from an image pickup device, comprising execution position selecting means for selecting the position of execution of the enlargement process by the enlargement process means, display means for displaying the state of selection by the execution position selecting means, and switching means for selectively switching an operative state or a non-operative state of the enlargement process means, wherein the display means displays the state of selection of the execution position selecting means at least when the switching means switches the enlargement process means to the non-operative state.
Also the foregoing object can be attained, according to another preferred embodiment of the present invention, by an image processing apparatus provided with enlargement process means for enlarging the image signals output from an image pickup device, comprising position selecting means for selecting the position of execution of the enlargement process by sid enlargement process means, display means for displaying the state of selection by the position selecting means, switching means for selectively switching an operative state or a non-operative state of the enlargement process means, and storage means for storing the information on selection by the position selecting means, wherein the display means displays the state of selection by the position selecting means at least when the switching means switches the enlargement process means to the non-operative state, and the position selecting means is adapted to operate based on the information on selection by the position selecting means, stored in the storage means, and the information on selection by the position selecting means is not stored in the storage means when the switching means switches the enlargement process means to the operative state.
Also the foregoing object can be attained, according to another preferred embodiment of the present invention, by an image processing apparatus provided with enlargement process means for enlarging the image signals output from an image pickup device, comprising position selecting means for selecting the position of execution of the enlargement process by the enlargement process means, display means for displaying the state of selection by the position selecting means, first switching means for selectively switching an operative state or a non-operative state of the enlargement process means, storage means for storing the information on selection by the position selecting means, and second switching means for selectively switching an operative state or a non-operative state of the position selecting means, wherein the display means is adapted to display the state of selection by the position selecting means at least when the second switching means switches the position selecting means to the operative state and the first switching means switches the enlargement process means to the non-operative state; the position selecting means is adapted to operate based on the information on selection of the position selecting means, stored in the storage means, when the first switching means switches the enlargement process means to the operative state; the state of selection of the position selecting means is not stored in the storage means when the first switching means switches the enlargement process means to the operative state; and a predetermined value is stored in the storage means when the second switching means switches the position selecting means to the non-operative state.
Also the foregoing object can be attained, according to another preferred embodiment of the present invention, by an image processing apparatus in which the aforementioned position selecting means is composed of viewpoint detecting means for detecting the position of the viewpoint of the photographer at the phototaking operation, the aforementioned execution position selecting means is composed of a tracking ball, a joy stick or a touch panel, and the aforementioned display means is composed of an electronic view finder.
Thus the position of execution of the enlargement process by the enlargement process means can be selected by the manipulation of the position selecting means by the photographer, and the state of the selection can be displayed by the display means.
Also the position of execution of the enlargement process by the enlargement process means can be selected by the manipulation of the position selecting means by the photographer, while the state of the selection can be displayed by the display means, and the state of selection by the position selecting means is displayed on the display means at least when the switching means switches the enlargement process means to the non-operative state.
The foregoing object can also be attained, according to another preferred embodiment of the present invention, by an image processing apparatus provided with enlargement process means for enlarging the image signals output from an image pickup device, comprising execution position selecting means for selecting the position of execution of the enlargement process by the enlargement process means, and enlargement ratio selecting means for selecting the enlargement ratio of the enlargement process by the enlargement process means.
Also the foregoing object can be attained, according to another preferred embodiment of the present invention, by an image processing apparatus provided with enlargement process means for enlarging the image signals output from an image pickup device, comprising execution position selecting means for selecting the position of execution of the enlargement process by the enlargement process means, enlargement ratio selecting means for selecting the enlargement ratio of the enlargement process by the enlargement process means, and display means for displaying the state of selection by the execution position selecting means and the enlargement ratio selecting means.
Another object of the present invention is to provide an image processing apparatus capable of so controlling the enlargement ratio or the enlargement position as that the image after the enlargement process does not overflow the image area.
Still another object of the present invention is to provide an image pickup device capable, at an image enlargement process, of causing the detection areas for auto focusing and auto exposure to follow the enlarged image, thereby enabling to maintain a satisfactory phototaking state during the image enlargement process.
Still other objects of the present invention, and the features thereof, will become fully apparent from the following description, which is to be taken in conjunction with the attached drawings.